Structural Analysis of a 4-Layer Curved Alternating Gradient Canted-Cosine-Theta Magnet Applied for Light-Weight Gantry

Superconducting magnets are preferable for the gantry applied to particle therapy, which are ascribed to their higher magnetic fields and relatively smaller size/weight compared to normal conducting magnets. Due to the large excitation current and inconsistent coefficient of thermal expansion of the different materials of the superconducting alternating gradient canted-cosine-theta magnet (AG-CCT), the Lorentz force and thermal stress are two main considerations in the AG-CCT structural analysis. However, a lot of computing power and time are needed to finish the AG-CCT full model stress analysis because of the complex structure of the mandrel. In this paper, a curved tube without ribs is employed to accelerate the stress analysis process. In the area with stress concentrations, the stress values with radial distribution on the mandrel are compared between the simplified model and the real AG-CCT model. The result shows that the relative deviation of stress in most regions is less than 10$\%$. Besides, a fast-modeling process was presented which can generate the AG-CCT model in an hour.